Wednesday, December 23, 2015

Understanding the Solstice

The first day of winter and the shortest day of the year begin tomorrow, December 22, the day of the Winter solstice. At 4:48 am Greenwich Mean time, the Solstice will arrive. The word solstice is relatively old in English, dating back to the 13th century. Solstice derives from the Latin word solstitium meaning very literally the point at which the sun stands still, a combination of the words sol meaning sunand the past participial stem of sistere meaning to come to a stop, make stand still. Celebrated thoughout history as either a secular or religious day, the solstice marks the point on the ecliptic when the Northern Hemisphere is pointed most away from the sun and therefore has the shortest day.

The easiest way to visualize the effect of the Earth’s orbit around the sun and the changing seasons is to view it from space. Above, the winter and summer solstices and the vernal and autumnal equinoxes from 2011. On the equinox (Latin for equal night) you can clearly see that the shadow is straight up and down, giving us equal day and night, while in the solstices, the Earth is either inclined toward or away from the Sun,
giving us days and nights of different lengths. For reference, find
the Arabian peninsula in the upper right quadrant of each image. The
second illustration shows what it looks like the Sun is doing, but remember that we travel around the Sun, not the other way around.

No comments:

About Me

"Blue" in Blue in the Bluegrass refers to my politics, not my state of mind, although being progressive-democratic in Kentucky is not for the faint of heart.
The Bluegrass Region of Kentucky is Central Kentucky, the area around Lexington. It's also sometimes known as the Golden Triangle, the region formed by Louisville in the west, Cincinnati in the north and Lexington in the east-south corner. This is the most economically advanced, politically progressive and aesthically beautiful area of the state. Also the most overpopulated by annoying yuppies and the most endangered by urban sprawl.
A Yellow Dog Democrat is one who will vote for even a yellow dog if it is running as a Democrat. I can't claim to be quite that fanatically partisan, especially since quite a few candidates who run as Democrats in Kentucky are more Republican than a lot of Republicans I can name.
But I do love the story Kentucky House leader Rocky Adkins never tires of telling about the old-timer in Eastern Kentucky who was once accused of being willing to vote for Satan if Satan ran as a Democrat. Spat back the old-timer:
"Not in a primary, I wouldn't!"
Amen.